Urodynamics Testing: What It Is and When You Need It

Urodynamics testing is an in-office procedure for men and women, typically in a urologist's or urogynecologist's office, to help determine how well the bladder is storing urine without leakage and how well it is emptying urine upon controlled demand. The tests are most often arranged for men with an enlarged prostate gland where obstruction due to enlargement needs to be better understood for treatment options and for women with incontinence that has either failed conservative treatment or requires surgery, especially if prolapse might be present. It is a means of refining diagnosis to help direct the practitioner treatment choices and subsequent steps to recommend to the patient.   Because some people have multiple problems involving storage and emptying, it is helpful for the doctor to determine which are the principle factors influencing symptoms so as to determine priorities in intervention, as well.

A patient may have difficulty describing what they are experiencing and may not even be the best source for determining a diagnosis, much less a course of treatment. For example, a patient complaining of urinary urgency (or rushing to the toilet), with increased frequency of urination might be considered to have overactive bladder. The cause of this might be detrusor overactivity, in which the bladder muscle experiences contractions to empty, or it might be the result of blockage of urine flow from the bladder to the body's outlet because of an enlarged prostate, in the case of a male patient.

Specific tests may be as simple as a patient urinating behind a curtain while a doctor or nurse listens or a more complicated series of tests, involving imaging equipment that films urination and pressure monitors that record the pressures of the bladder and urethra, might be undertaken. Urodynamics testing typically involves equipment and is a quantitative testing maneuver. A typical urodynamic test takes about 45 minutes.  It is entirely out-patient and performed in the doctor's office.  It involves the use of a small catheter inserted to fill the bladder and record measurements. What is done depends on what identifying problems surface, but typical tests are:

  • Measurement of urine remaining in the bladder after it's been voluntarily emptied.

  • Sampling of urine for microscopy and culture to check for infection.

  • Uroflowmetry, which measures how fast the patient can empty his/her bladder and the rate at which it flows (how much over time).

  • Cystometry, which measures the pressure in the rectum and in the bladder to determine the presence of contractions of the bladder wall during bladder filling. The strength of the urethra can also be tested during this phase, using a cough or Valsalva manouvre, to confirm genuine stress incontinence.

  • Urethral pressure profilometry, is conducted to measure the strength of sphincter contraction.

  • Electromyography (EMG) measurement of electrical activity in the neck of the bladder, or sphincter muscle. The "tightness" along the length of the urethra is measured as well.

  • Fluoroscopy (moving video x-rays) of the bladder and bladder neck during voiding.

The series of tests, while not considered particularly painful, are uncomfortable and embarrassing for many patients. The chair, the patient's position, one's exposure to others, and the testing means themselves, are considered stressful. A provocative upright cystometry is used for example rather than a supine position.   People feel very exposed, both men and women, particularly the elderly.

The most important thing to ask before scheduling this or any other series of tests is: 1) what can be learned that is not already known, and 2) what will be done with this additional information in treatment of my symptoms.   Patients should also ask and be aware of what tests cost, regardless of whether Medicare or private carriers pay for the procedures and interpretation of results by their doctors. Just because a procedure is covered by insurers, public or private, doesn't mean they are justified and necessary. Don't wait until you show up for the procedure to ask these questions.   Get the facts up front in discussion with your doctor who is suggesting them.

Remember that ultimately we all pay for healthcare delivery in the country, either directly through taxes, premiums, or by out of pocket cash payments. Our nation needs to curtail unnecessary tests that are used to simply verify what clinicians already know. We must be comfortable with the rationale and necessity of each and every test, as every procedure has its risks and vulnerabilities.